The present invention relates in general to a magnetic circuit for DC electromagnet such as a relay electromagnet, which comprises a fixed core, two yokes each connected to a respective free end of the core, and at least one armature movable between two end positions, said armature comprising a permanent magnet having flux input and output faces disposed at right angles to the magnet axis and each provided with a pole piece, each yoke having a flat portion having at least one air gap surface, the flat portions of the yokes being located in substantially parallel planes, said pole pieces having projecting end portions provided with air gap surfaces located on either side of the magnet axis, the flat portion of a first one of said yokes having two air gap surfaces and penetrating with a clearance corresponding to the armature stroke, between the two mutually facing air gap surfaces of the two end portions of the pole pieces located on a first side of the magnet axis.